Kickout valve and circuit

ABSTRACT

A kickout valve for use in a machine having a part moved by hydraulic pressure under control of a manual control valve which has a detent for holding it in an actuating position. The kickout valve is engaged when the movable part reaches a pre-established position. The valve is opened and admits fluid under pressure through a circuit leading to the control valve, where it causes release of the detent and allows the control valve to seek a closed or hold position and the moving part to come to rest.

United States Patent Borer et al. [451 June 20, 1972 [54] KICKOUT VALVEAND CIRCUIT 3,161,307 12/1964 Schick et al. ..2l4/764 [72] Inventors:Herbert W. Borer, Naperville; John R. 325L492 5/1966 i at 214/762 XCryder Edward A wim both of Joliet 3,289,546 12/1966 Erickson ..91/358 Aa 3,420,393 1/1969 Omon ..91/358 A [73] Assignee: Caterpillar TractorCo., Peoria, 111. imary Examiner-Martin P. Schwadron AssistantExaminer-Irwin C. Cohen [22] Filed Sept 1970 AttameyFryer, Tjensvold,Feix, Phillips & Lempio and Mar- 21 Appl. No.: 69,009 tin Majestic [57]ABSTRACT 52 us. c1. ..91/3ss A, 91/410, 251/251 [51] wFlsb 13/01, Flsb13/16 A klckout valve for use in a machine having a part moved by 581Field of Search ..91/35s 358A 388 410- hydraulic Pressure under mmuul214/762 1 which has a detent for holding it in an actuating position.The

' kickout valve is engaged when the movable part reaches a pre- [56]References Cited established position. The valve is opened and admitsfluid under pressure through a circuit leading to the control valve, U DS ES PATENTS where it causes release of the detent and allows thecontrol 2 337 659 12/1943 H h t 1 251,251 x valve to seek a closed orhold position and the moving part to ug ey e a come to rest 2,537,7981/1951 Smith ..251/260 3,128,677 4/ 1964 Tennis ..137/624.27 X 5 Claims,5 Drawing Figures SHEET 1 2 INVENTORS E T E RRR mmw m m +T T cA A MEDHJE

PATENTEDJUH 20 m2 SHEET 2 0F 2 INVENTORS HERBERT W. BORER JOHN R. CRYDEREDWARD A. WIRTZ ATTORNEYS KICKOUT VALVE AND CIRCUIT BACKGROUND OF THEINVENTION It has become common practice in machines having componentsmoved by hydraulic pressure to use control valves with detents to holdthem in an activating position until the component reaches a desiredpoint and then to cause automatic kickout or release of the detent anddeactivation of the valve. This has the advantage of freeing anoperator's hands for other duties and allowing him to devote hisattention to other necessary operations. Examples of such kickout meansare found in our assignees patents to Beck, US. Pat. No. 3,122,247; toMuellner, et al., US Pat. No. 3,155,252; to Freedy, et al., US. Pat. No.3,234,855; and to Erickson, U.S. Pat. No. 3,289,546.

All of the patents referred to above relate to kickout or controlmechanisms employed on tractor mounted bucket loaders, and the presentinvention will be described in this environment by way of one example ofits intended use.

It is the object of the invention to improve upon kickout mechanisms andcircuits by providing a very simple, durable and reliable valvemechanism and by providing a circuit for said valve mechanism whichutilizes the pressure of fluid in the main actuating circuit forreleasing the detent in a control valve. Other objects and advantageswill become apparent upon an understanding of the following descriptionwherein reference is made to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of ahydraulic circuit for actuating a hydraulic motor and including thekickout valve and kickout circuit of the present invention;

FIG. 2 is a schematic central sectional view of the kickout valve takenon the line II--Il of FIG. 1;

FIG. 3 is a fragmentary detail in section taken on the line IlI-lll ofFIG. 2;

FIG. 4 is a schematic view of an alternative embodiment of the inventionshowing a different mechanism for actuating the kickout valve; and

FIG. 5 is a detail taken on the line V-V of FIG. 4.

DETAILED DESCRIPTION Referring first to FIG. I, afluid motor isrepresented as a hydraulic jack generally indicated at which may, forthe purposes of the present description, be considered the lift jackwhich raises and lowers the lift arms of a bucket loader. A pump 12directs fluid under pressure from a suitable reservoir through a controlvalve generally indicated at 14 to either end of the jack 10 while fluidfrom the opposite end is returned to the reservoir.

The control valve 14, which is conventional, has four positionsgenerally referred to as float, lower, hold and raise, and it is shownin the raise position in which it is held by a detent urged by a spring16 into a detent groove 17 within the spool 18 of the valve. A centeringspring of conventional construction, generally illustrated at 19, tendsto return the spool 18 to its hold position, closing all communicationbetween the jack and the pump as well as between the jack and thereservoir.

In the raise position of the valve illustrated, the pump is directingfluid under pressure to a line 20 and to the head end of the jack 10extending its rod and raising the loader lift arms (not shown). Thefluid in the rod end of the jack is being exhausted through line 22 andcontrol valve 14 to the reservoir.

The kickout valve of the present invention, generally indicated at 24,is normally closed but when its actuating lever shown at 26 is engagedby a cam 28 on the rod of the jack, it will be moved to an open positionand fluid pressure from the pump and in the line 20 will be communicatedthrough a branch line 30 and through the valve 24 to a line 32 whichcommunicates with the detent groove control valve and causes retractionof the detent which permits the centering spring 19 to move the valve toits hold position.

The construction of the kickout valve 24 is shown in FIGS. 2 and 3wherein a spring biased ball check 36 normally closes communicationbetween the lines 30 and 32. A reciprocable plunger 38 which rests onthe ball functions to open the valve against the bias of the spring. Theopposite end of the plunger 38, as shown in FIGS. 2 and 3, normallyengages the flattened portion 40 of a rotatable shaft 42 to which lever26 is secured. Rotation of the lever, therefore, when it is engaged bythe cam 28 on the rod of the jack brings the full diameter of the shaft42 into contact with the plunger 38and opens the valve to permit returnof the control valve to its neutral or hold position as previouslydescribed.

During the moment when the check valve 36 is open, pres sure from line30 may escape into the chamber which contains the shaft 42 and any fluidescaping into this chamber is relieved back to the reservoir as througha vent line shown at 44 in FIGS. 1 and 2.

Kickout valve 24 includes a torsion spring 46 which is coiled around oneend of shaft 42 and has one end 48 disposed in a hole 50 of lever 26 tourge the lever in a counter-clockwise direction (as seen in FIG. 1)against a positive stop 52. Stop 52 also serves to fix the other end 54of the torsion spring. When lever 26 is against the stop, fluid flowthrough valve 24 is blocked, thereby interrupting flow to the detentmechanism. Retraction of cylinder rod 56 supporting cam 28 enables thetorsion spring to return the lever to its normal position in which itabuts the stop.

Referring now to FIG. 4 there is shown an alternative embodiment of theinvention wherein kickout valve 24 is secured to a bracket 58 which ismounted on the rod end 59 of cylinder 10' by means of bolts 60 andspacers 62. The hydraulic circuit utilized with this embodiment is notshown since it is identical to that shown in FIG. 1 for the firstembodiment. Instead of utilizing a cam to actuate the valve as with thefirst embodiment, a striker rod 64 which is attached to rod 56' inparallel, spaced relation thereto by clamp means 66 and slidablyextending through hole 68 in the bracket is used.

Upon retraction of rod 56' into cylinder 10', the free end 70 of strikerrod 64 engages a roller 72 which is secured to lever 26 and forces thelever in a counter-clockwise direction (as seen in FIG. 4) against thebias of torsion spring 46.

The structure and operation of valve 24' is identical with valve 24 ofthe first embodiment. It should be noted that, like parts of the secondembodiment are identified by addition of a prime to their numberdesignation in the first embodiment. As aforementioned with the firstembodiment, rotation of lever 26' against the bias of torsion spring 46'causes the control valve to return to a hold position, thereby stoppingthe retraction of rod 56'.

In addition, the control valve can be manually manipulated to causefurther retraction of rod 56' whereupon the underside of striker rod 64holds lever 26' in the thus manually rotated position. Upon extension ofrod 56' from cylinder 10, the striker rod end 70 moves away from roller72, thereby al lowing spring 46 to return lever 26 to its normalposition abutting stop 52'.

It is to be understood that the foregoing description is merelyillustrative of a preferred embodiment of the invention and that thescope of the invention is not to be limited thereto, but is to bedetermined by the scope of the appended claims.

What is claimed:

1. In a hydraulic system comprising a hydraulic motor, a source of fluidunder pressure, a first, control valve having an open position fordirecting fluid from said source to said motor for operation thereof, aspring means normally closing said control valve, a detent means forholding said valve in the open position, a line communicating; pressurefrom between said control valve and said motor for releasing said detentmeans, a second, kickout valve in said line, said kickout valve beingspring biased by kickout spring means to a normally closed position,means movable by said motor for opening said kickout valve therebyreleasing said detent means and allowing the spring means of said first,control valve to return said first valve to its normally closed positionwherein operation of the hydraulic motor is stopped, said kickout valveincluding a lever which is spring biased by said kickout spring meansagainst a stop in its normally closed position, said motor comprising acylinder having a cylinder rod reciprocally extendable from one endthereof, said means on said motor for opening said kickout valvecomprising means on said cylinder rod for engaging said spring biasedlever and wherein said kickout valve and lever are so positioned withrespect to said cylinder rod as to be in the path of said means on saidcylinder rod for opening said kickout valve when said rod is actuated,and wherein said kickout valve comprises a body, a first passage withinsaid body having a reciprocable plunger therein, one end of said firstpassage being in fluid communication with said line, a ball check biasedby a ball spring means contained within said first passage andcontacting one end of said plunger as well as closing said first passageby sealing against a portion of said first passage, a second passage insaid body at right angles to and intersecting said first passage, arotatable shaft contained within said second passage and having a flatportion thereon receiving the other end of said plunger, a third passagewithin said body communicating said detent means and said first passagebetween said ball check and said second passage, said plunger being of alength with relation to the spacing of said flat portion to said ballcheck such that said ball check sealingly closes said first passage whensaid flat portion of said rotatable shaft is in contact with said otherend of said plunger and wherein when said rotatable shaft is rotated tobring said other end of said plunger into contact with the full diameterof the shaft, said plunger displaces said ball check from its sealingposition against said portion of said I passage against the bias of saidball spring means and thereby allows fluid under pressure to flow fromsaid line, through said first passage and around said spring and saidball check and into said third passage and hence into the detent means.

2. The system of claim 1 wherein said rotatable shaft is an elongatedmember having one end within said body and the other end extendingtherefrom, and said lever is an elongated member having one end fixed tosaid other end of said shaft.

3. The system of claim 1 wherein said means on said cylinder rod foropening said kickout valve comprises a cam projection on said rod.

4. The system of claim 1 wherein said means on said cylinder rod foropening said kickout valve comprises a striker rod mounted in parallel,spaced relation to said cylinder rod.

5. The system of claim 4 wherein said kickout valve is mounted on theend of said cylinder by means of a bracket fastened thereto, saidstriker rod is an elongated member which is fixed at one end by clampmeans to said cylinder rod, said bracket having a hole therethrough, thefree end of said striker rod extending through said hole in saidbracket, and said rod being so positioned such that the free end thereofengages said lever for actuation of said kickout valve when saidcylinder rod is retracted.

1. In a hydraulic system comprising a hydraulic motor, a source of fluidunder pressure, a first, control valve having an open position fordirecting fluid from said source to said motor for operation thereof, aspring means normally closing said control valve, a detent means forholding said valve in the open position, a line communicating pressurefrom between said control valve and said motor for releasing said detentmeans, a second, kickout valve in said line, said kickout valve beingspring biased by kickout spring means to a normally closed position,means movable by said motor for opening said kickout valve therebyreleasing said detent means and allowing the spring means of said first,control valve to return said first valve to its normally closed positionwherein operation of the hydraulic motor is stopped, said kickout valveincluding a lever which is spring biased by said kickout spring meansagainst a stop in its normally closed position, said motor comprising acylinder having a cylinder rod reciprocally extendable from one endthereof, said means on said motor for opening said kickout valvecomprising means on said cylinder rod for engaging said spring biasedlever and wherein said kickout valve and lever are so positioned withrespect to said cylinder rod as to be in the path of said means on saidcylinder rod for opening said kickout valve when said rod is actuated,and wherein said kickout valve comprises a body, a first passage withinsaid body having a reciprocable plunger therein, one end of said firstpassage being in fluid communication with said line, a ball check biasedby a ball spring means contained within said first passage andcontacting one end of said plunger as well as closing said first passageby sealing against a portion of said first passage, a second passage insaid body at right angles to and intersecting said first passage, arotatable shaft contained within said second passage and having a flatportion thereon receiving the other end of said plunger, a third passagewithin said body communicating said detent means and said first passagebetween said ball check and said second passage, said plunger being of alength with relation to the spacing of said flat portion to said ballcheck such that said ball check sealingly closes said first passage whensaid flat portion of said rotatable shaft is in contact with said otherend of said plunger and wherein when said rotatable shaft is rotated tobring said other end of said plunger into contact with the full diameterof the shaft, said plunger displaces said ball check from its sealingposition against said portion of said passage against the bias of saidball spring means and thereby allows fluid under pressure to flow fromsaid line, through said first passage and around said spring and saidball check and into said third passage and hence into the detent means.2. The system of claim 1 wherein said rotatable shaft is an elongatedmember having one end within said body and the other end extendingtherefrom, and said lever is an elongated member having one end fixed tosaid other end of said shaft.
 3. The system of claim 1 wherein saidmeans on said cylinder rod for opening said kickout valve comprises acam projection on said rod.
 4. The system of claim 1 wherein said meanson said cylinder rod for opening said kickout valve comprises a strikerrod mounted in parallel, spaced relation to said cylinder rod.
 5. Thesystem of claim 4 wherein said kickout valve is mounted on the end ofsaid cylinder by means of a bracket fastened thereto, said striker rodis an elongated member which is fixed at one end by clamp means to saidcylinder rod, said bracket having a hole therethrough, the free end ofsaid striker rod extending through said hole in said bracket, and saidrod being so positioned such that the free end thereof engages saidlever for actuation of said kickout valve when said cylinder rod isretracted.